With the increase in global population and the vagaries of weather, water conservation has become a significant cause, not only in this country but throughout the world. It has been recognized that clean potable water be conserved and used primarily for those purposes where its qualities of cleanliness and purity are necessary, and other uses, such as the flushing of toilets, be accomplished utilizing so called "gray water". Gray water is generally defined as the "effluent" from household systems, such as household sinks and showers, laundry washing machine and dishwasher discharge. Such systems, although sufficiently contaminating the water so that its potability is compromised, do not so contaminate the water as to render it unfit for use for the flushing of toilets. Accordingly, a great many systems have been previously developed for such purposes, i.e., the recycling of such gray water for use in flush toilets.
The household plumbing systems in most modern municipalities are fully developed. One reason why gray water systems have not found greater usage is the cost of replacing the present plumbing system for one which can utilize the previously available gray water recycle systems.
Other methods of conserving water concern the elimination of the runoff or overflow of excess unused water and the use of the least amount of water feasible for flushing toilets. Such methods can be applied to fresh water plumbing systems or, preferably, for increased conservation, to gray water systems.
Ball cock valves and other mechanical valves are inefficient and waste water, for example, from leakage or imprecise filling resulting in overflows. Thus, any improvement in the valve used in flush tanks would conserve water. Electrical valves have been introduced for both the convenience and precision they afford. Such valves include U.S. Pat. No. 3,505,689 to Neff, U.S. Pat. No. 2,717,396 to Chiles, U.S. Pat. No. 4,380,835 to Yao, U.S. Pat. No. 3,090,967 to Erhardt, and U.S. Pat. No. 4,225,986 to Mauk.